Sears 9MPD, N9MP2 Sizing, Insulation, Filters, Filter Installation using Optional Filter Rack

CARBON MONOXIDE POISONING HAZARD

This could result in death, personal injury and/or

property damage.

Cool air passing over heat exchanger can cause

condensate to form resulting in heat exchanger failure.

Connections

NOTE: On upflow installations, return air can enter through either side, both sides, orthe bottom. On horizontal or downflowinstalla-

tions the return air must enter through the knockout opening in the lower panel of the furnace. Return air can not enter through rear of the furnace. When the furnace is located in an area near or ad-

jacent to the living area, the system should be carefully designed

with returns to minimize noise transmission through the return grille. Any blower moving a high volume of air will produce audible

noise which could be objectionable to when the unit is located very close to living areas. It is advisable to route the return air ducts under the floor or through the attic.

1. Forsideconnectionsusinga16"x25"filter,cutouttheem- bossed area shown in Figure 33. This will provide a 141/2"

x 221/2" approximate opening.

i;[ :;; [

Side Return Air C UtO Ut

iiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiii

Height of Cutout for 16" x 25" Filter

AB==221/z"141/z" Width of Cutout for 16" x 25" Filter/_

on Side of Furnace

Embossed Area _jmC e

NOTE: Furnaces with 5 TONS cooling rating require two(2) side returns or one side return with bottom return.

2.Bottom returns can be made by removing the knockout panel in the furnace base. Do NOT remove knock-out ex- cept for a bottom return.

3.Installation of locking-type dampers are recommended in all branches, or in individual ducts to balance system's air flow.

4.Non-combustible, flexible duct connectors are recom-

mended for return and supply connections to furnace.

5.If air return grille is located close to the fan inlet, install at least one, 90 ° air turn between fan and inlet grille to reduce noise.

NOTE: To further reduce noise, install acoustical air turning vanes and/or line the inside of duct with acoustical material.

Sizing

Existing or new ductwork MUST be sized to handle the correct amount of airflow for either heating only or heating and air condi- tioning.

Insulation

1.Insulate ductwork installed in attics or other areas exposed

to outside temperatures with a minimum of 2" insulation and vapor barrier.

2.Insulate ductwork in indoor unconditioned areas with a minimum of 1" insulation with indoor type vapor barrier.

Filters

A Filter must be used:

Filters are not supplied with these furnaces, but can be purchased from dealer.

Use either filter type:

•Washable, high velocity filters are based on a maximum air flow rating of 600 FPM.

•Disposable, low velocity filters are based on a maximum air flow of 300 FPM when used with filter grille.

NOTE: Disposable, low velocity filters may be replaced with washable, high velocity filter providing they meet the minimum size areas. Washable, high velocity filters can be replaced ONLY with same type and size.

Side Mounted Filter Rack

25-20-90

Filter Installation using Optional Filter Rack

When installing or removing a bottom mounted filter, slide the two side filter clips to the back of the furnace BEFORE installing or re- moving. This will allow the filter to clear the front raised edge of the furnace. Insert filter into side clips first and push filter back until it is fully engaged into back clip. When filter is in place, slide clips back into place midway on filter as shown in Figure 35.

Bottom Mounted Filter Rack

25-24-18

Slide filter clips towards back before removin_l

Refer to Figure 36 and for guidelines to install filters. Furnaces which require larger filter media and have limited clearances on

44001 111400